1. Technical Field
This invention generally relates to a wall shelf system. More particularly, to an elongated wall shelf support bracket which is attached to a vertical surface and supports, in cantilevered fashion, a glass or other non-ligneous material wall shelf.
2. Background Art
Cantilevered wall shelves have become increasingly popular over the years as a substitute for more expensive and space consuming bookcase or shelf furniture. The early applications of cantilevered wall shelves utilized some variation of a peg boards or vertical wall standards and brackets to fully support the entire width of a wood shelf. These wall support systems had obvious utilitarian value, however they were not particularly attractive in appearance and design, and as a result were a poor substitute for bookshelves and other types of shelving furniture for ruse in the living areas of a home or apartment.
Ornamental wall shelves in common usage today are cantilevered and incorporate a design feature wherein the screws used to attach the bracket to the wall are concealed behind the shelf or under a closeable facing. Typically an elongated slot is formed in the wall bracket for receiving the wall shelf. The general design problems which the prior art attempt to overcome are twofold. The first is to firmly hold the shelf in cantilevered fashion so that it does not wobble, and secondly, to fasten the rear portion of the shelf to the wall brackets so that it cannot be inadvertently or accidentally dislodged by contact or intentionally pulled from its bracket as, for example, by a young child.
Typical of such early attempts are MacDONALD, U.S. Pat. Nos. 3,471,111 and 3,471,112, which feature a lower support bracket insertable into a hole drilled into a wall surface. The MacDonald brackets contemplate the use of at least two brackets to support any particular shelf. The problem is that the shelf support brackets are difficult to fasten to a wall, and more adapted for use against a wood surface as opposed to a drywall, plaster or sheetrock wall surface.
LOUI, ET AL., U.S. Pat. No. 4,037,813, represents an improvement over the MacDonald shelf support brackets in that means are provided to frictionally engage a resilient shelf to hold it in a wedged, cantilevered position. In the embodiment suitable for use with a glass shelf, this wedging cantilivered system requires the application of downward forces on the elongated shelf at the point where it is supported by the lower support surface, to cause it to pivotally force the rear edge of the shelf up against an upper support surface to hold the cantilevered shelf in position. The problem with Loui, et al. is providing a means to hold the shelf in the bracket in a manner such that it cannot be easily and accidentally removed either by someone brushing up against the shelf, or a child attempting to pull it out from the wall.
ROBERTS, ET AL., U.S. Pat. No. 4,385,565, attempts to solve the problem of inadvertent removal of the shelf from the support bracket by use of an inwardly inclined retaining ridge for gripping or digging into the shelf in the event that someone attempts to remove it. However the Roberts shelf support is not suitable for use with a glass or other non-ligneous material shelf, in that the retaining ridge would not grip against the glass surface, and the glass shelf would wobble. As a result, Roberts teaches a second embodiment without the retaining ridge for use with a glass shelf. But again, no provision is made to prevent its accidental removal. NICHOLSON, ET AL., U.S. Pat. No. 4,508,301 is another variation of the inventive concepts disclosed in Roberts, et al. Again, it requires the use of ligneous material for the shelves to provide the resiliency to allow effective use of the system to hold the shelf in the bracket.
BESSINGER, U.S. Pat. No. 4,691,887 is a first attempt at providing a retentive shelf anchor for a glass wall shelf. It incorporates the use of a resilient polymeric insert having elongated flexible fingers extending downwardly and rearwardly to provide a retention force to the top of a glass wall shelf. While Bessinger, U.S. Pat. No. 4,691,887 represents an improvement over the prior art in that it does provide some retention forces for a glass shelf, it suffers from a number of drawbacks, not the least of which is the fact that the glass shelf can still be easily and accidentally removed from the bracket. Additionally, it requires the installation of a resilient insert into an elongated slot in the wall shelf bracket. This can be difficult in cases where the elongated bracket is of some substantial length itself.
As a result, there have been additional attempts to provide a secure retentive anchoring system for glass wall shelves. BESSINGER, U.S. Pat. Nos. 4,733,843, 4,736,918 and 4,736,919 teach three additional designs for anchoring a glass wall shelf to a support bracket. In Bessinger U.S. Pat. No. 4,733,843 the shelf bracket is provided with a pair of lower support members, the innermost one of which is brought into compressive engagement with the glass shelf by means of a set screw. This is a complicated design, and a relatively expensive product to manufacture. In Bessinger U.S. Pat. No. 4,736,918 another design is disclosed which teaches the use of a concealed set screw which is inserted through a preformed hole in the glass shelf. And finally, Bessinger, U.S. Pat. No. 4,736,919 provides for a shelf bracket where a set screw engaged in a fixed traveler nut is used to bear directly against the glass shelf. In all these cases it is possible to impose excessive compressive forces upon the glass shelf thereby causing it to fracture and break.
HOLZTRAGER, U.S. Pat. No. 4,752,010 teaches a display wall system which utilizes plastic or possibly glass wall shelving held in cantilevered fashion by means of upper and lower double sided tapes which attach the shelf to opposing upper and lower shelf support brackets. It is not a suitable design for a single shelf residential unit.
Accordingly, what is needed is a wall shelf system which provides a shelf bracket for use with a glass shelf, wherein once the glass shelf has been inserted into the bracket it can no longer be removed therefrom except by means of a determined pull, and which does not utilize set screws which can impart excessive compressive forces to the shelf, thereby causing it to fracture and break. A second object is to provide a wall shelf bracket which is of simple design and amenable to fabrication by simple die extrusion processes. A final object is a fabrication of the wall shelf system which is attractive and pleasing to the eye.